Integrated petroleum refining process



Dec. 1, 1964 J. w. SPRAGUE INTEGRATED PETROLEUM REFINING PROCESS FiledDec. 4, 1962 M H m w m T mW A M J I! w J M m 2/ 5 m J m T Q N k m @N w 9$5580? J g on m 4 k i QOEEQQQI I J 3 J Q mNK r w NI W J m f g m A| T H m$595 y m 6 R55 1. w 8 mk i fl AL N United States Patent 3,159,566INTEGRATED PETRGLEUM REFINING PRUCESS .iames W. Sprague,Streetshoro,@hio, assignor to The fitandard Gil Company, Cleveland,fihio, a corporation of Ohio Filed Dec. 4, 1962, Ser. No. 242,179 2Claims. (Cl. 203-79) The present invention relates to an integratedpetroleum refining process involving a particular combination of anumber of petroleum refining processes. The cornination which forms thesubject matter of this invention results in a process whereby crude oilis converted to substantially completely gasoline and lighter productswith a minimum simultaneous production of products heavier than gasolinesuch as furnace oils and the like.

A substantial research effort is devoted by the petroleum refiningindustryto the development of ways and means for maximizing the amountof gasoline which may be obtained from a given quantity of crude oil.Efiorts toward achieving this objective have been stimulated by the factthat, in general, gasoline is a more economically desirable product thanheavier products such as furnace oil, diesel fuel, bunker fuel, and thelike. The maximum amount of gasoline obtainable from a given quantity ofcrude oil has been limited by the available technology and furtherimprovements in this area have awaited the development of new processingtechniques. It is, therefore, one object of this invention to provide anintegrated refining process by means of which it is possible to obtain agreater quantity of gasoline froma given quantity of crude oil than hasbeen heretofore possible.

In brief, the invention relates to a process for the treatment of crudeoil involving a combination of fractionation, catalytic reforming,fiuorotreating, hydrocracking, and hydrogenation. The manner in whichthese processes are combined in accordance with the present inventioncan best be explained by reference to the attached patent drawing. Inthis drawing, the process is represented by a schematic flow diagram.Pumps, heat exchangers, valves and other conventional equipment are notshown on the drawing since they would add nothing to an understanding ofthe invention. A written description of the flow diagram now follows.

Referring now to the attached patent drawing, crude oil is introducedthrough line 10 into a crude still 11 where it is divided into fourfractions, viz.;

(1) An overhead fraction which includes the VC; hydrocarbons.

(2 A light naphtha fraction including 0 and c hydrocarbons.

(3) A heavy naphtha fraction, suitable for reforming,

having an end-point of 380 F.-

(4) A bottomsfraction having an initial boiling point of 380 F., andcomprising the remainder of the crude oil. l

The overhead fraction consisting of the lighter components is processedin a gas plant which is unrelated to the process of this invention andit leaves the process] via line 12. The light naphthafraction isrecovered'as 3,35%,556 Patented Dec. 1, 1964 tionator 22 via line 21 tothe gasoline blending plant which is not a part of this invention.

The bottoms fraction obtained from the crude still 11 is transferredthrough line 13 to a fluorotreater unit 17. Hydrogen fluoride is addedto the fluorotreater unit 17 through line 16. Treated product istransferred from the fiuorotreater unit 17 through line 18 to acatalytic hydrocracking unit 19. Efiiuent from the hydrocracking unit 19is transferred through line 28 to a fractionator 29. In the fractionator29 the efiluent from the hydrocracking unit 19 is divided into threefractions including a light ends fraction, a distillate fraction havingan end point of 380 F. and a bottoms fraction having an initial boilingpoint of 380 F. The light ends fraction leaves the process via line 31for further treatment in the gas plant which is not related to thepresent invention. The intermediate distillate fraction is transferredthrough line 30 to line 14 where it is mixed with the incoming feed tothe catalytic reforming unit 15.

The bottoms fraction from fractionator 29 is transferred through line 27to a catalytic hydrogenation unit 25 via line 23. Returning now to thebottoms fraction from fractionator 22, this fraction is also transferredby means of line 23 to the hydrogenation unit 25. Hydro gen is added tothe hydrogenation unit 25 through line 24. Effluent from hydrogenationunit 25 is returned to the hydrocracking unit through lines 26 and 18. Adetailed description of the various processing steps now follows.

In the first step in the process, crude oil is fractionated into fourseparate fractions. The first fraction comprises the lighter componentsof the crude oilup to and including the C fraction. The second or lightnaphtha fraction comprises the C and C hydrocarbons. The third, or heavynaphtha fraction is suitable for reforming and has an end point of 380F. The bottom fraction comprises thoseheavier components of the crudeoil boiling initially at 380 F. A conventional fractionating towercomprising a plurality of bubble-cap trays may be used for a crude oildistillation of the type here contemplated.

The initial fraction of the crude oil comprising those hydrocarbonsboiling up to and including the C hydrocarbons is transferred to a gasplant for further treatment which forms no part of this invention. Thesecond, or light naphtha fraction may be transferred to a fuel blendingstorage and is not further concerned. with the integrated process ofthis invention. The third fraction of the crude oil, namely that portionhaving an end point of 380 F., is transferred to a conventionalcatalytic remeans are conventional and the pretreatment is usually aside stream of line12a and canbe transferred directly w to fuel blendingstorage facilities. and thereafter is not concerned with the integratedprocess of this invention. The heavy naphtha fraction is transferredthrough line .14 to a catalytic reforming unit 15. Effluent from thelatter unit is transferred through conduitZtB to a fracfluent boilingbelow 380 F. is transferred from the fracaccomplished by passing thefeed over a bed of cobalt 'rnolybdatecatalyst in the presence of addedhydrogen ditions depending upon the desired octane level of the product.Liquid hourly space velocities of one to six vol- 3- umes of hydrocarbonper volume of catalyst per hour are employed. A hydrogen-rich gas isseparated from the reaction efilucnt and recycled to the reactors withthe feed at a rate of 1000 to 10,000 s.c.f. of hydrogen per barrel ofcharge.

Effluent from the catalytic reforming unit is transferred to aconventional fractionator wherein a bottom fraction boiling above 380 F.is obtained and sepm'atcd for further treatment in accordance with theprocess of this invention. The fraction boiling below 380 F. istransferred to a gasoline blending plant for further treatment which isnot a part of this invention.

The bottom fraction of the crude oil, namely, that fraction boilingabove 380 F. is transferred to a fluorotreater. In this treater thebottoms fraction is contacted with 0.5 to 1.0% of gaseous hydrogeniluoride based on the weight of the oil at a temperature in the range of75 to 200 F. This treatment is designed to remove a part of the nickeland essentially all of the other metal contaminants normally containedin this fraction as well as any nitrogenous compounds which may bepresent since all of these materials are known to have a deleteriouseffect upon hydrocracking catalysts. Very small concentrations of thesecontaminants in the feed streams will lead to rapid poisoning of thecatalyst in the subsequent hydrocracking process, whereas hydrogenfluoride Wlil coagulate these contaminants and permit their readyremoval without the formation of an acid sludge due to chemicalreactions involving other constituents of the oil. The fluorotreatingprocess is thus a selective one in which the yield of decontaminated oilis quite high, usually on the order of about 95%. Since the hydrogenfluoride is not consumed in the sludging reactions with the oil, it maybe recovered and reused repeatedly. The material which is coagulated bythe action of the hydrogen fluoride may be removed from the oil by anynumber of well-known separation methods, such as settling, filtration,or centrifugation. The eliluent from the fiuorotreating unit which issubstantially free of deleterious metal and nitrogen compounds is nexttransferred to a hydrocracking process.

Hydrocracking processes are usually operated at pressures on the orderof 500 to 5000 psi, preferably in the range of 800 to 1000 psi. and attemperatures in the range of 550 to 625 F. it is necessary to addhydrogen to the feed to a hydrocracker at a rate generally in the rangeof 1000 to 100,000 s.c.f. of hydrogen per barrel of feed, 5000 to 10,000s.c.f. of hydrogen per barrel of feed ordinarily being sufficient. Spacevelocities on the order of 0.5 to 5 volumes of hydrocarbon per volume ofcatalyst per hour are employed.

Hydrocracking catalysts are of the so-called dual functional type. Suchcatalysts contain an acidic ingredient which serves as the crackingelement in the catalyst and materials such as silica-alumina,silica-magnesia, silicaalumina-zirconia, beryllium oxide, indium oxide,fluorinated alumina or various acid-treated clays may be employed as theacidic constituent. The other element of the catalyst is thehydrogenation ingredient and it may be selected from the metals ofGroups V to VIII of the Periodic Table and/or their oxides or sulphides.Illustrative of such materials are the oxides and/ or sulphides ofmolybdenum, tungsten, vanadium, and chromium. Other materials such asthe oxides of iron, nickel and cobalt may also be employed. In generalthe hydrogenating ingredient will comprise 0.1 to 20% by weight f thehydrocracking catalyst.

The etlluent from the hydrocracking process is fractionated inconventional equipment into three fractions. The lightest fraction istransferred to a gas plant for further treatment which forms no part ofthe present invention. An intermediate fraction which includes the Chydrocarbons and has an end point of 380 F. iscombined with thepretreated virgin feed to the catalytic reformer. It has been observedthat a hydrocraclzed distillate makes a better quality feed to thecatalytic reforming process than a virgin material of the same boilingrange and the process of this invention makes use of this fact.

The bottom fraction of the cfiluent from the hydrocracking unit whichhas an initial boiling point of 380 F. is combined with a bottomfraction having the same initial boiling point which is obtained byfractionation of the effluent from the catalytic reforming unit asdescribed above. This combined stream is transferred to a catalytichydrogenation unit and this step forms one of the key steps in theprocess. Neither of the materials making up this stream would make asatisfactory feed to a hydrocracking process because of the fact thatthey are largely condensed aromatic and consequently they are verydifficult to crack. However, under severe hydrogenation conditions therelatively refractory aromatic compounds can be converted intonaphthcnic compounds which may be cracked with considera ly greaterfacility. Hence, the hydrogenation step malzes it possible to continuerecycling the heaviest fractions from the hydrocracker and the reformerto virtual extinction so that only products boiling within the gasolinerange or lighter are produced ultimately by this process.

Catalytic hydrogenation units are customarily operated at fairly highpressures on the order of 1,000 to 5,000 p.s.i. and preferably about3,000 psi. Temperatures on the order of 450 to 750 F. and preferably inthe range of 500 to 600 F. are usually employed. Substantial quantitiesof hydrogen are required in the process and the ratio of hydrogen tohydrocarbon charge should be on the order of 2000 s.c.f. of hydrogen perbarrel to 100,- 000 s.c.f. of hydrogen per barrel. The space velocitymay vary from 0.5 to one volume of hydrocarbon per volume of catalystper hour. A strong hydrogenation catalyst such as nickel or nickelsupported on kicselguhr must be employed in this step of the process.The eflluent from the hydrogenation unit is returned as feed to thehydrocracking unit where it is treated along with the virgin feed.Hence, the production of products heavier than gasoline is substantiallyeliminated.

A specific example of the process of this invention is as follows:

A desalted Illinois Basin crude oil having the properties listed inTable I was used.

TABLE I Properties of Desalled Illinois Basin Crude Gravity, API 35.9Specific gravity 0.8453

Pour point, F. 35 Total sulfur, wt. percent 0.25 Asphaltenes, wt.percent 0.3 Viscosity, SSU, at 72 F 53.1 Viscosity, SSU, at 100 F. 47.2Viscosity gravity constant 0.821 Reid vapor pressure, p.s.i. 5.20Nitrogen, wt. percent 0.149 Mercaptan sulfur, pounds per 1000 barrels13.8 H 8 sulfur, pounds per 1000 barrels 22.6 Ramsbottom carbon (calc.wt. percent) 2.66 Neutralization number 0.0634- Vanadium, parts permillion 2 Nickel, parts per million 5.5 Iron, parts per million 2.9

The crude is introduced, at a rate of one thousand barrels per day,through line 10 into crude still 11 where it is divided into fourfractions. The overhead stream, leaving the crude still by means of line12, contains mixed butanes, produced at a rate of 21 barrels a day, anda dry gas portion produced at a rate 4560 standard cubic feet per dayand having the composition indicated in Table II. Line 12 conveys thisoverhead stream to a gas plantfor further processing not furtherconcerned with the integrated proccss of this invention.

Component:

TABLE 11 a Dry Gas Composition Component:

, Percent Non-condensables 8.3 Methane 0.5 Ethane 0.2 Propane 91.0

The light naphtha side-stream, leaving the crude still by means of line12a consists of mixed pentanes and hexanes, produced at a rate of 84barrels per day and having the properties shown in Table III. This lightside stream is transported to fuel blending storage and is not furtherconcerned with the integrated process of this invention.

TABLE III Properties of Pentane-Hexane Side Stream Specific gravity0.6883 A.P.I. gravity degrees 74.1 Percent sulfur 0.015 Mercaptansulfur, pounds per 1000 barrels 3.3 H 8 sulfur, pounds per 1000 barrels0.1

The heavy naphtha fraction, produced at a rate of 196 barrels per day,and having the properties shown in Table IV, is transferred through line14 to the catalytic reforming unit 15 (cornbinedwith 334 barrels perday'of the intermediate fraction from fractionator 29 to give a totalreformer feed of 530 barrels per day).

TABLE iv Properties of Heavy Naphflm API gravity Q degrees 54.7 Specificgravity 0.7600 Percent sulphur 0.031 Mercaptan sulfur, pounds per 1000barrels 8.6 Basic nitrogen, parts per million 0.6 Percent paraiiins 40Percent aromatics 7 Percent naphthenes 53 Initial boiling point, F. g207 point, F. 218 30% point, F. 251 50% point, F. 279 70% point, F. 31390% point, F. 350 Endpoint, F. 376

Thecatalytic reforming unit .15 is charged with 4425 pounds of aplatinum-germanium on chlorided alumina catalyst (containing 0.35percentplatinum and 0.13 percent germanium) and is operated under conditions ofa temperature of 925 degrees F., a pressure of 500 p.s.i.g., a weighthourly space velocity of 1.33 and 6000 standard cubic feet of recyclegas per barrel of liquid feed. The efiiuent from the catalytic reformingunit is transferred through line 20 to a fractionator 22 where afraction boiling below 380 F. is removed from the fractionator via line21. This reformer'product stream, when fractionated by equipment nototherwise directly 'concerned with the integrated process of thisinvention, produces 124,000 standard cubic feet of gas per day havingthe composition shown in Table V, 29 barrels per day of mixed butanesand 422 barrels per day of liquid reformate, having the properties shownin Table VI, which is transferred to the gasoline blending plant (nototherwisea part of this invention).

. TABLE V Reformer Gas Product COmpOitiOib This reformer gas is suitableas process gas for the hydrocracking operation and may be convenientlycycled to to hydrocracker 19 for this purpose.

TABLE VI Reformaze Properties Gravity, API 42.6 Specific gravity 0.8112

The bottoms fraction obtained from the crude still 11, having theproperties shown in Table VII, is transferred at a rate of 695 barrelsper day through line 13 to the fluorotreater unit 17. Hydrogen fluorideis added to the fluorotreater unit 17 through line 16 at a rate, of 2050pounds per day to produce 8,222 pounds per day of sludge containing 18percent hydrogen fluoride. The supernatant fiuorotreater stock is heatedin a stream of inert gas at about 375 F. to remove dissolved hydrogenfluoride to produce 676 barrels per day of a treated stock having theproperties shown in Table VIII. The sludge is heated to recover 98.6percent of the total hydrogen fluoride which is then recycled to thefiuorotreater.

TABLE VII Properties of 380 F. Crude Fraction Gravity, API 26.6 Specificgravity 0.8951

Sulfur, percent 0.24 Nitrogen, percent 0.197 Vanadium, parts per million2.9 Nickel, parts per million 7.9 Iron, parts per million 4.2 Rarnsbottom carbon 3.53 Initial boiling point, F. 402 10% point, F 43830% point, F. Q. 567 50% point, F. 1 713 point, F. a 911 Thefluorotreater effluent is transferred through line 18 (at a rate of 676barrels per day) to the catalytic hydro cracking unit 19 (combined with107 barrels per day of hydrogenerator effluent to give a totalhydrocracker'feed of 783 barrels per day) which is charged with 6760 vpounds of a tungsten disulfide on silica -alumina (30 percent alumina)catalyst prepared by impregnation of silica alumina with silico tungsticacid followed by reduction in a stream of hydrogen sulfide at 500 to 700degrees P. so as to contain 4.2 percent of tungsten disulfide in thefinished cat'alyst. The hydrocracking unit 19 is-operatecl underconditions of a temperature of 650 degrees F, a pressure of 2000p.s.i.g., a' liquid hourly space velocity of 1.5, and a hydrogen feed of2700 standard cubic feet per barrel of liquid feed.

7 TABLE VIII Properties of Fluorotreater Effluent Gravity; API

Specific gravity 0.8914

Sulfur, percent a 0.22

2.01 V Vanadium, parts perjmillion 4 TABLE VllL-Continued Nickel, partsper million 3.3 Iron, parts per million 0.0

The eflluent from the hydrocracking unit 19 is transferred through line28 to a fractionator 29 where it is divided into three fractions. Thelight ends fraction is sent by line 31 to further fractionation (notdirectly concerned with the integrated process of this invention) toproduce 355 barrels per day of a light naphtha having the propertieslisted in Table IX, 185 barrels per day of mixed butanes with an iso tonormal ratio of 5.37, and 69,800 standard cubic feet per day of dry gashaving the composition shown in Table X.

TABLE IX Properties of Hydrocracker Light Naphtha Gravity, API 80.5Specific gravity 0.6676

The intermediate distillate fraction from the fractionator 29, havingthe properties shown in Table XI, is produced at a rate of 334 barrelsper day and transferred by means of line 30 to line 14 where it is mixedwith the incoming feed to the catalytic reforming unit 15.

TABLE XI Properties of Hydrocracker Intermediate Distillate Gravity, APl50.9 Specific gravity 0.7760

Paraffins, percent 49.0 Aromatics, percent 15.0 Naphthenes, percent 36.0Sulfur, percent 0.00 Nitrogen, parts per million 0.3 Initial boilingpoint, F. 218 point, F. 240 30% point, F. 268 50% point, P. 300 70%point, F. 335 90% point, P. 363 End point, F. 379

The bottoms fraction from fractionator 29, which is a highly aromaticmaterial containing many bicyclic compounds and having the propertiesshown in Table XII, is produced at a rate of 80 barrels per day and istransferred through line 27 to the catalytic hydrogena-. tion unit vialine 23.

TABLE XII Properties of Hydrocracker Bottoms Fraction Gravity, API 11.6Specific gravity 0.9891

Sulfur, percent 0.01 Nitrogen, percent 0.008 Initial boiling point, F.396 10% point, F. 44-3 point, F. 483 50% point, F. 528 70% point, F. V592 90% point, F. 735 End point, F. 863

The bottoms fraction from fractionator 22, a highly aromatic materialproduced at a rate of 9 barrels per cases 8 day and having theproperties shown in TABLE XIII, is also transferred by means of line 23to the hydrogenation unit 25 to provide a combined feed to this unit of89 barrels per day. The hydrogenation unit 25 is charged with 512 poundsof fifty percent nickel on kicselguhr catalyst and operated underconditions of a tem- Jerature of 550 degrees, F., a pressure of 2000p.s.i.g., a weight hourly space velocity of 0.4 and 10,000 standardcubic feet of gas recycle per barrel of liquid feed.

TABL XIII Properties of Reformer Bottoms Fraction Gravity, API 4.8.Specific gravity 1.038. Boiling range a Above 380 F.

The effluent from the hydrogenation unit 25, having the properties shownin Table XIV, is produced at a rate of 107 barrels per day and istransferred by means of lines 26 and 18 to the hydrocracking unit 19where it is recessed as described above.

TABLE XIV Properties of Hydrogenation Unit Product Gravity, APT 32.6Specific gravity 0.8622 Initial boiling point, F. 391 10% point, F. 40930% point, F. 441 50% point, "P. 492 point, F. 568 point, F. 729 Endpoint, F. 870

It will be apparent from the foregoing description that the process ofthe present invention will offer important economic advantages to thosepetroleum refiners who desire to minimize their production of productsheavier than gasoline. Many modifications of the process willundoubtedly occur to those skilled in the art and this application forLetters Patent is intended to covor all such modifications as wouldreasonably fall witi in the scope of the appended claims.

I claim:

1. An integrated petroleum refining process comprising the steps of (a)fractionating a crude oil into an overhead frac tion, a light naphthafraction, a heavy naphtha fraction, and a bottoms fraction,

(1)) subjecting said heavy naphtha fraction obtained in step (a) to acatalytic reforming operation,

(c) fractionating the catalytic reformate obtained in step (b) into atleast two fractions,

(d) treating the bottoms fraction obtained in step (a) with hydrofluoricacid whereby nitrogeneous and metallic compounds are removed therefrom,

(e) subjecting said treated bottoms fraction obtained in step (d) to acatalytic hydrocracking operation,

(1) fractionating the hydrocracked eflluent from step (e) into alightfraction, an intermediate distillate fraction and a bottoms fraction,

(g) combining the intermediate fraction obtainedin step (f) with thefeed to step (b) and subjecting same to a catalytic reforming operation,

(/1) combining the bottoms fraction obtained in step (c) with thebottoms fraction obtained in step (i) and subjecting this stream to acatalytic hydrogenation operation,

(i) combining the hydrogenated effluent from step (/1) with the feed tostep (e) and catalytically hydrocracking same.

2. An integrated petroleum refining process compris ing the steps of.(a) fractionating'a crude oil into an overhead fraction, a lightnaphtha fraction including C and C hydrocarbons, a heavy naphthafraction having an 9 end-point of about 380 F. and a bottoms fractionhaving an initial boiling point of about 380 F.

(b) subjecting said heavy naphtha fraction obtained in step (a) to acatalytic reforming operation,

(0) fractionating the catalytic reformate obtained in step ([2) into alight fraction, and into a heavy fraction having an initial boilingpoint of 380 F.

(d) treating the bottoms fraction obtained in step (a) with gaseoushydrofluoric acid whereby nitrogeneous and metallic compounds areremoved therefrom,

(e) subjecting said treated bottoms fraction obtained in step (d) to acatalytic hydrocracking operation,

(1) fractionating the hydrocracked effluent from step (e) into a lightfraction, an intermediate distillate fraction boiling within thegasoline boiling range and a bottoms fraction having an initial boilingpoint of about 380 F.

(g) combining the intermediate fraction obtained in step (1) with thefeed to step (b) and subjecting same to a catalytic reforming operation,

(h) combining the bottoms fraction obtained in step (c) with the bottomsfraction obtained in step (1) and subjecting this stream to a catalytichydrogenation operation,

(i) combining the hydrogenated efiluent from step (h) with the feed tostep (e) and catalytically hydrocracking same.

References Cited in the file of this patent UNITED STATES PATENTS 152,859,169 Herman Nov. 4, 1958 2,971,905 Bieber et a1. Feb. 14, 19612,973,313 Pevere et a1. Feb. 28, 1961

1. AN INTEGRATED PETROLEUM REFINING PROCESS COMPRISING THE STEPS OF (A)FRACTIONATING A CRUDE OIL INTO AN OVERHEAD FRACTION, A LIGHT NAPHTHAFRACTION, A HEAVY NAPHTHA FRACTION, AND A BOTTOMS FRACTION, (B)SUBJECTING SAID HEAVY NAPHTHA FRACTION OBTAINED IN STEP (A) TO ACATALYTIC REFORMING OPERATION, (C) FRACTIONATING THE CATALYTIC REFORMATEOBTAINED IN STEP (B) INTO AT LEAST TWO FRACTIONS, (D) TREATING THEBOTTOMS FRACTION OBTAINED IN STEP (A) WITH HYDROFLUORIC ACID WHEREBYNITROGENEOUS AND METALLIC COMPOUNDS ARE REMOVED THEREFROM, (E)SUBJECTING SAID TREATED BOTTOMS FRACTION OBTAINED IN STEP (D) TO ACATALYTIC HYDROCRACKING OPERATION, (F) FRACTIONATING THE HYDROCRACKEDEFFLUENT FROM STEP (E) INTO A LIGHT FRACTION, AN INTERMEDIATE DISTILLATEFRACTION AND A BOTTOMS FRACTION, (G) COMBINING THE INTERMEDIATE FRACTIONOBTAINED IN STEP (F) WITH THE FEED TO STEP (B) AND SUBJECTING SAME TO ACATALYTIC REFORMING OPERATION, (H) COMBINING THE BOTTOMS FRACTIONOBTAINED IN STEP (C) WITH THE BOTTOMS FRACTION OBTAINED IN STEP (F) ANDSUBJECTING THIS STREAM TO A CATALYTIC HYDROGENATION OPERATION, (I)COMBINING THE HYDROGENATED EFFLUENT FROM STEP (H) WITH THE FEED TO STEP(E) AND CATALYTICALLY HYDROCRACKING SAME.